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<DIV dir=ltr align=left><SPAN class=031173814-12012009><FONT face=Arial
color=#0000ff size=2>Dear Ulrik,</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=031173814-12012009><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=031173814-12012009><FONT face=Arial
color=#0000ff size=2>Regarding "conditioned space":</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=031173814-12012009><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=031173814-12012009><FONT face=Arial
color=#0000ff size=2>"Conditioned space" seems pretty straightforward to
me. If, for example, the cooling system for a 10,000 sq.ft. space
has 10 tons cooling capacity, then the capacity is 12Btu/hr/ft2 (10tons x
12,000 Btu/hr/ton / 10,000 ft2) This exceeds the ASHRAE threshold of 5
Btu/h/ft2, so it's "conditioned". If the cooling system was only 4 tons,
it would not be "conditioned" (only 4.8 Btu/hr/ft2).</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=031173814-12012009><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=031173814-12012009><FONT face=Arial
color=#0000ff size=2>The definition depends only indirectly on "U" values and
wall areas. For any given construction, you choose to provide an air
conditioning system or not. You can also choose to cool a lot or a
little. Each choice affects whether you end up with an air conditioning
system greater than 5 Btu/hr/ft2 or not.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=031173814-12012009><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=031173814-12012009><FONT face=Arial
color=#0000ff size=2>Heating works the same way, except the threshold varies by
climate zone.</FONT></SPAN></DIV>
<DIV> </DIV>
<DIV class=Section1>
<P class=MsoNormal style="TEXT-ALIGN: center" align=center><B
style="mso-bidi-font-weight: normal"><FONT size=4>The Building Performance
Team<BR></FONT></B><B style="mso-bidi-font-weight: normal">James V. Dirkes II,
P.E., LEED AP<BR></B>1631 Acacia Drive NW<BR>Grand Rapids, MI 49504<BR>616
450 8653<?xml:namespace prefix = o ns =
"urn:schemas-microsoft-com:office:office" /><o:p></o:p></P>
<P class=MsoNormal><o:p> </o:p></P></DIV>
<DIV> </DIV><BR>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left>
<HR tabIndex=-1>
<FONT face=Tahoma size=2><B>From:</B> bldg-sim-bounces@lists.onebuilding.org
[mailto:bldg-sim-bounces@lists.onebuilding.org] <B>On Behalf Of </B>Ulrik
Welle-Strand Horn<BR><B>Sent:</B> Saturday, January 10, 2009 9:47
AM<BR><B>To:</B> bldg-sim@lists.onebuilding.org<BR><B>Subject:</B> [Bldg-sim]
ASHRAE 90.1 Definition of "Conditioned" - The PRM Reportfor LEED EAc1 and
Appendix G Energy Model<BR></FONT><BR></DIV>
<DIV></DIV>Dear All,<BR><BR>I would like to know if and how you consider
ASHRAE's definition of conditioned space on page 13 of the 2004
version.<BR><BR>Specifically, I am interested to know if you abide by this
definition when listing the conditioned vs unconditioned area? The definition
seems really specific to me, explaining how the system serving a conditioned
area must have a certain capacity per square foot of building area served. It
even goes on to explain how for some spaces one must consider the sum of the
products of various U-factors and wall areas. To me, it does not seem like one
can eyeball all these comparisons and definitions and therefore one has to go
ahead and measure the capacities of systems and compare them with the area they
serve, as well as do computations for rooms that might be indirectly
conditioned.<BR><BR>The PRM report for LEED requires you to list unconditioned
and conditioned areas separately. Do any of you actually go through the
calculations to find out if each single space in your project complies with the
definitions put forward in the 90.1 document? It seems to me like more effort
than what it's worth. I don't recall ever using this classification of
unconditioned vs conditioned anywhere else in the LEED certification process.
Especially, I don't recall ever having to use this definition to do the PRM
model itself under Appendix G. Has anyone come across another place than the PRM
report where the efforts of classifying their spaces accoring to the 90.1
definition above has been rewarded? Please also let me know if any one of you
have ever experienced trouble getting your project LEED certified because of
lack of compliance with this definition.<BR><BR>Lastly, the definition
explicitly states that "Crawlspaces, attics, and parking garages with natural or
mechanical ventilation are not considered enclosed spaces." Do most of you
usually leave out car parks from the PRM area report? I am working on a building
where about 60% of the floor area is parking space, meaning the sum total in my
Space Summary will be much less than stated otherwise in the documents submitted
to USGBC. I know that they are looking for all the total areas to be pretty
consistent, and that some people experience problems when thes total areas don't
match up. Has anyone ever dealt with this issue? If so, how did you deal with
it?<BR><BR>I appreciate any response you may have to any or all of my
questions.<BR><BR>Sincerely yours,<BR><BR><BR><B>Ulrik Welle-Strand Horn
</B><BR>Sustainability Engineer<BR>
<DIV><BR><B>Silpa Inc.</B><BR><FONT size=1><B>s</B> i m p l e .
<B>s</B> c i e n t i f i c . <B>s</B> u s t a i n a b l
e<BR></FONT></DIV><FONT size=1>
<DIV>AMERICAS | MIDDLE EAST | ASIA<BR><A href="http://www.silpainc.com/"
target=_blank>www.silpainc.com</A><BR></DIV><FONT size=2><BR></FONT></FONT><FONT
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